D2D communications refers to direct communications between two communication devices (e.g., user equipment (UE)). This is unlike conventional communication in a cellular-type network where communications take place between an enhanced Node B (eNB) (e.g., base station) and the communication devices. In conventional cellular-type networks, the eNB schedules and allocates channel resources. For D2D communications however, the amount of control overhead and delay associated with scheduling and allocating resources for D2D communications by the eNB may be prohibitive. This is particularly an issue in situations with a large volume of D2D communications. Furthermore, in some situations, the eNB may be unavailable for scheduling and allocating resources for D2D communications.
Thus there are general needs for more efficient methods of scheduling and allocating resources for D2D communications in cellular-type networks, such as 3GPP-LTE networks. There are also general needs for methods of scheduling and allocating resources for D2D communications that do not rely on or require an eNB or base station. There are also general needs for methods of scheduling and allocating resources for D2D communications that reduce the amount of control overhead and delay. There are also general needs for methods of scheduling and allocating resources for D2D communications that minimize power consumption for transmission and idle modes, support spatial-reuse and provide for variable size resource allocations.